#region PDFsharp - A .NET library for processing PDF
//
// Authors:
//   Stefan Lange
//
// Copyright (c) 2005-2017 empira Software GmbH, Cologne Area (Germany)
//
// http://www.pdfsharp.com
// http://sourceforge.net/projects/pdfsharp
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
// DEALINGS IN THE SOFTWARE.
#endregion

namespace PdfSharp.Pdf.AcroForms
{
    /// <summary>
    /// Represents an interactive form (or AcroForm), a collection of fields for
    /// gathering information interactively from the user.
    /// </summary>
    public sealed class PdfAcroForm : PdfDictionary
    {
        /// <summary>
        /// Initializes a new instance of AcroForm.
        /// </summary>
        internal PdfAcroForm(PdfDocument document)
            : base(document)
        {
            _document = document;
        }

        internal PdfAcroForm(PdfDictionary dictionary)
            : base(dictionary)
        { }

        /// <summary>
        /// Gets the fields collection of this form.
        /// </summary>
        public PdfAcroField.PdfAcroFieldCollection Fields
        {
            get
            {
                if (_fields == null)
                {
                    object o = Elements.GetValue(Keys.Fields, VCF.CreateIndirect);
                    _fields = (PdfAcroField.PdfAcroFieldCollection)o;
                }
                return _fields;
            }
        }
        PdfAcroField.PdfAcroFieldCollection _fields;

        /// <summary>
        /// Predefined keys of this dictionary. 
        /// The description comes from PDF 1.4 Reference.
        /// </summary>
        public sealed class Keys : KeysBase
        {
            // ReSharper disable InconsistentNaming

            /// <summary>
            /// (Required) An array of references to the document’s root fields (those with
            /// no ancestors in the field hierarchy).
            /// </summary>
            [KeyInfo(KeyType.Array | KeyType.Required, typeof(PdfAcroField.PdfAcroFieldCollection))]
            public const string Fields = "/Fields";

            /// <summary>
            /// (Optional) A flag specifying whether to construct appearance streams and
            /// appearance dictionaries for all widget annotations in the document.
            /// Default value: false.
            /// </summary>
            [KeyInfo(KeyType.Boolean | KeyType.Optional)]
            public const string NeedAppearances = "/NeedAppearances";

            /// <summary>
            /// (Optional; PDF 1.3) A set of flags specifying various document-level characteristics
            /// related to signature fields.
            /// Default value: 0.
            /// </summary>
            [KeyInfo("1.3", KeyType.Integer | KeyType.Optional)]
            public const string SigFlags = "/SigFlags";

            /// <summary>
            /// (Required if any fields in the document have additional-actions dictionaries
            /// containing a C entry; PDF 1.3) An array of indirect references to field dictionaries
            /// with calculation actions, defining the calculation order in which their values will 
            /// be recalculated when the value of any field changes.
            /// </summary>
            [KeyInfo(KeyType.Array)]
            public const string CO = "/CO";

            /// <summary>
            /// (Optional) A document-wide default value for the DR attribute of variable text fields.
            /// </summary>
            [KeyInfo(KeyType.Dictionary | KeyType.Optional)]
            public const string DR = "/DR";

            /// <summary>
            /// (Optional) A document-wide default value for the DA attribute of variable text fields.
            /// </summary>
            [KeyInfo(KeyType.String | KeyType.Optional)]
            public const string DA = "/DA";

            /// <summary>
            /// (Optional) A document-wide default value for the Q attribute of variable text fields.
            /// </summary>
            [KeyInfo(KeyType.Integer | KeyType.Optional)]
            public const string Q = "/Q";

            /// <summary>
            /// Gets the KeysMeta for these keys.
            /// </summary>
            internal static DictionaryMeta Meta
            {
                get
                {
                    if (s_meta == null)
                        s_meta = CreateMeta(typeof(Keys));
                    return s_meta;
                }
            }
            static DictionaryMeta s_meta;

            // ReSharper restore InconsistentNaming
        }

        /// <summary>
        /// Gets the KeysMeta of this dictionary type.
        /// </summary>
        internal override DictionaryMeta Meta
        {
            get { return Keys.Meta; }
        }
    }
}